The ARP Quartet was made by Seil (an Italian synthesizer manufacturer) and relabeled and sold by ARP. It specialized in string, brass, organ, and piano sounds.

"The Brass section on the Quartet offers a choice of two brass footages (8' and 16'), in the form of Trumpet and Trombone voicings. Because the Quartet's preset voices are mixable, the Brass section can be combined with other preset voices. A brass chorus with delayed vibrato or string and brass orchestra are just two of the many polyphonic effects that can be created in this manner. The Brass section features independent control of attack and sustain.

"The Quartet's String section includes Cello and Violin chorus voicings, plus a choice of percussive or solo settings. Again, the String sections can be mixed with other sections to produce a pop organ, using percussion, solo, or organ and strings. The attack and sustain of the String section may be varied by using the String Section's independent attack and sustain sliders.

"Two Organ voices are preset on the Quartet. The Organ and the Celeste can be played either independently or in combination with other instrumental sounds. The pop organ patch on the Quartet takes on an added dimension when the Celeste is added, producing a rotating speaker effect. Double footages on the Organ setting produce a full, rich tone unparalleled in the Quartet's price range.

"The Piano section offers the Musician a choice between Piano and Honky Tonk, either or both of which can be mixed with the Quartet's other sections. With the Piano section, a musician can produce both a 4' and Grand Harpsichord, with variable sustain.

"Twelve LED status lights let the musician know which functions are in use at all times. A foot switch permits prolonged release on all selected voices. An optional optical volume pedal is also available for the Quartet.

"The Master tuning control is conveniently located to the right of the keyboard. The Quartet is manufactured in a sturdy aluminum frame with genuine wood endblocks.."----[from the ARP Quartet promotional brochure courtesy of Kevin Lightner]